Bene clavel



Patented Oct. 6, 1931 RENE CLAVEL, F BASEL-AUGST, SWITZERLAND TREATMENT OF ARTIFICIAL SILKS 1T0 Drawing. Original application filed Kay 27, 1927, Serial No. 194,859, and in'Germany September 17, 1928. Divided and this application filed March 27, 1928. Serial No. 265,234.

This invention relates to processes for weighting artificial silks.

This application is a division of my copending application Serial No. 194,859 filed .5 May 27, 1927 As is known, the weighting of artificial silks presents very considerable difiiculties, owing to the fact that artificial fibres of cellulose or cellulose derivatives are very sensitive to the action of weighting agents and in many cases to the action of water. The many pas sages of the hanks or fabrics through a series of baths containing separately the individual weighting agents, as is customary in natural silk weighting processes and through the intermediate washing or neutralizing baths. which are necessary between the actual weighting baths. are particularly unfavorable for artificial silks. In the case of artificial silks made from cellulose esters. apart from the iniury to the fibres. a saponification of the cellulose esters often occurs. by which the silk sufi'ers and frequently becomes useless. The aim of artificial silk weighting must therefore be to effect the weighting in as few baths as possible.

I have now found that very successful weighting of artificial silks may be obtained bv employing successive weighting baths (impregnating and precipitating baths) without intermediate washing or neutralizing. the fibre and /or at least one of the baths having added or applied thereto a substance adapted to hinder premature precipitation, i. e. precipitation either in the bath or at the surface of the fibre.

Such substances may be mineral or organic acids. acid salts or salts having an acid reaction or protective colloids such as glue. gelatine. albumen or the like. If desired the substance used t'o'hinder premature precipita- .tion may itself be a weighting substance. Thus for example aluminium sulphate has a verypronounced acid reaction and may act at'the same time as a weighting agent.

One or more of the said agents adapted to hinder precipitation may be applied to the goods. or to at least one of the baths. or both to the goods and at least one of the baths, and the goods passed successively through the baths without intermediate washing or neutralizing. As examples of the successive weighting baths may be mentioned baths of tin or zinc compounds and of salts such as phosphates, sulphates, for instance of alumina, or silicates, or of acids, for example phosphoric acid.

By means of the invention the weighting of artificial silks can be effected by passing through only a comparatively small number of baths. neutralizing and washing being eliminated. and further the hanks. fabrics or other goods need only remain in the baths a very short time to obtain the required weighting.

In order to obtain a better fixation of the weighting agents and in certain cases in order to remove excess of acid. the materials after weighting and preferably after squeezing may be treated in a bath having an alkaline reaction, for example a solution of ammonium carbonate, to which if desired dyestuffs which contain tanning substances, such as haematein, may be added.

The invention is applicable (6 the weighting of all art ficial silks made from cellulose or cellulose derivatives. for example acet l cellulose silks, viscose silks, Chardonnet sil s and cuprammonium silks.

The following examples may be given in illustration of the invention, it being understood that they are in no way limitative and can be varied widely without departing from the spirit of the invention.

Example 1 10 litres of the weighting bath contain:

200 grams zinc chloride. 100 grams sulphate of aluminium. 400 grams anhydrous tin chloride.

Eimmple i! A fabric consisting wholly or partly of acetyl cellulose artificial silk, e. g. a crepe de chine fabric, is led in full through a 1% aqueous solution of phosphoric acid containing 12 grms. or glue per litre. The fabric is then carried directly through four tin chloride baths containing tin tetrachloride solution of 35 Be strength and is thereafter squeezed and led first into a 10% monosodium phosphate bath and then into 6% disodium phosphate bath. After the alkaline phos phate bath the fabric is hydro-extracted and may if desired be finallytreated in a waterglass solution of 1 Be containing 1 gm. of soap per litre.

Emampie 3- An artificial silk fabric is passed on a finishing machine through a 1.0 litre bath con taining 400 grms. of zinc chloride and 100 grms. of formic acid. The fabric is then passed directly without washing through a 68% aqueous solution of monosodium phosphate. The artificial silk may then be squeezed, passed through a 5% solution 0:? ammonium carbonate and dried.

Example 4 Acetyl cellulose artificial silk in the form of hanks is immersed for a short time in a 1% solution of monochloracetic acid. The treated hanks are brought into a bath containing tin tetrachloride of 35 B and are then stretched and allowedto remain in the air for a short time. The procedure may be repeated if desired. The hanks are well centrifuged and entered for a short time into a 15% solution of monosodium phosphate. They are squeezed or hydroextracted and if desired after a short washing rnav be given a final treatment in a 1% solution of waterglass containing soap at 40 C.

Goods of acetyl cellulose or the like weighted according to the invention are increased comprising successively treating them wlth a in volume considerablv and have a much increased aflinitv for direct dyeing sulnhonated dyestuffs. which ordinarilv dve acetvl cellulose little or not at all. (lwing to the rela 'tivelv short duration of treatment in the baths their strength is substantially unimpaired.

Owing to the omission of intermediate washing or neutralization. diluted solutions of the weighting a gents or o? transformation products thcreoi resulting from neutralization are not obtained and in conscouencc the special installations and considerable expense usually entailed in the recovery of such agents or products are avoided.

An additional advantage accrues when a treatment of the goods with an acid substance is carried out prior to the weighting. it bci ng found that a more intensive and more uniform absorption of the weighting agents is brought about and the duration of the whole weighting process is considerably reduced.

What I claim and desire to secure by Letters Patent is 1. Process for weighting artificial silks comprising successively treating them with a plurality of weighting agents without intermediate washing and neutralizing, and emgloying at least one substance adapted to hiner premature precipitation.

2. Process for weighting acetyl cellulose artificial silks comprising successively treating them with a plurality of weighting agents without intermediate washing and neutralizing, and employing at least one substance adapted to hinder premature precipitation.

3. Process for weighting artificial silks comprising successively treating them with a plurality of weighting agents without intermediate washing and neutralizing, and employing at least one substance having an acid reaction and" adapted to hinder premature precipitation.

4. rocess for weighting acetyl cellulose artificial silks comprising successively treating them with a plurality of weighting agents without intermediate washing and neutralizing, and employing at least one substance having an acid reaction and adapted to hinder premature precipitation.

5. Process for weighting artificial silks comprising successively treating them with a plurality oi weighting agents without intermediate washing and neutralizing, and em ploying at least one acid adapted to hinder premature precipitation.

6. Process for weighting artificial silks comprising successively treating them with a plurality of weighting agents without intermediate washing and neutralizing. at least one of the baths containing the weighting agent containing a substance adapted to hinder premature precipitation.

7. Process for weighting artificial silks plurality of weighting baths without intermediate washing and neutralizing, at least one of the baths containing the weighting agent containing a substance having an acid reaction and adapted to hinder premature precipitation.

8. Process for weighting artificial silks comprising successively treating them with a plurality of weighting agents without intermediate washing and neutralizing, at least one of the weighting baths. containing an acid adapted to hinder premature precipitation.

9. A process for weighting artificial silks comprising treating them with a substance having an acid reaction and then successivelv treating them with a plurality of weighting agents without intermediate washing and neutralizing. there being present in at least one of the weighting baths a substance having an acid reaction and adapted to hinder premature precipitation.

16. Process for Weighting acetyl cellulose artificial silks comprisingftreating themwith a substancehavin anacid reaictionj and then successivelp treating them. with a plurality: of weighting agents Without intermediate washing and neutralizing, there'being present in at least one of the weighting baths a substance having an acid reaction and adapted to hinder premature precipitation.

- 11. Process for weighting artificial silks comprising treating them with an acid and thensuccessively treating them with a plu-1 rality of weighting baths without intermedi ate washing or neutralizing, there being present in at least one of the weighting baths an 5 zticid adapted to hinder premature precipitaion;

12. Process for weighting artificial silks comprising successively treating them with a scribed my name.

' RENE CLAVEL- plurality of weighting agents without intermediate washing and neutralizing, and employing at least one substance having an acid reaction and adapted to hinder premature precipitation, and thereafter treating the materials with an alkaline solution.

13. Process for weighting artificial silks comprising successively treating them with a plurality of weighting agents without inter-i mediate washing and neutralizing, there being present in at least one of the'weightin'g 3o baths a substance having an acid reaction and adapted to hinder premature precipitation,

and thereafter treating the materials with an .alkaline solution.

14. Process for weighting acetvl cellulose 35 artificial silks coniprising successively treating them with a plurality of weighting agents without intermediate washing and neutralizing. there being present in at least one of the weighting baths a substance having an acid reaction and adapted to hinder premature precipitation, and thereafter treating the materials with an alkaline solution.

' 15. Process for weighting artificial silks comprising treating the material with a substance having an acid reaction, then successively treating them with a plurality of weighting agents. there being present in at least one of the weighting baths a substance having an acid reaction and adapted to hinder premature precipitation, and thereafter treating the materials with an alkaline solu- .tion. v

16. Process for weighting acetyl cellulose artificial silks comprising treating the ma-' terial with a substance having'an acid reaction. then successivelv treating them with a plurality of weighting agents. there being present in at least one of the weighting baths a substance having an acid reaction and adapted to hinder premature precipitation, and hereafter treating the materials with ana aline solution.

17 Process for weighting artificial silks comprising successively treating them with a plurality of weighting agents without inter- 

